Flow regulation apparatus for brine injection wells



R. W. ERWIN Aug. 29, 1944.

FLOW REGULATION APPARATUS FOR BRINE INJECTION WELLS Filed June 8 1942jzalzsame Min.

INVENTOR. BY 20%? I Arm/nay Patented Aug. 29, 1944 FLOW REGULATIONAPPARATUS FOR BRINE INJECTION WELLS Ransome W. Erwin, Tyler, Tex.,assignor to Salt Water Control, Inc., Fort Worth, Tex.

Application June 8, 1942, Serial No. 446,193

13 Claims.

The invention relates to improvements in'methd and apparatus employed inthe regulation of the flow of water or brine to a disposal well in asystem of the general type disclosed in my prior Patents Nos. 2,261,057and 2,261,100, dated Octo- 'ber 28, 1941. It will be understood thatpreferably liquid to be introduced into the disposal well will have beenpreviously treated for the removal of oil and insoluble mineral foreignmatter, such as calcium, magnesium and iron compounds, by any suitablemeans such as disclosed, for example, in my Patents Nos. 2,261,057 and2,261,101.

In common with the disclosure of myPatents Nos. 2,261,057 and 2,261,100the present system of brine disposal preferably includes the steps ofintroducing the liquid into the upper portion of a disposal well havinga porous formation at the bottom thereof, preferably from an externalsource whose level is maintained above the level of the well, andcontrolling the flow of liquid through the well to said porous formationfrom a point in thewell located substantially below the point ofintroduction of the liquid, in accordance with variations in the liquidlevel of said source, in order to maintain a substantially continuouscolumn of liquid from said formation to said source so as to avoidcascadingand vacuum formation. I eifected by means of a weightedreciprocable valve automatically actuated in accordance withpredetermined variations in the liquid level within a surge tank locatedoutside of the well, so as to periodically cover or uncover an openingin a valve seat located within the well, preferably at a point below thenormal static water level, the covering or uncovering of the saidopening serving to alternately cut off or permit the flow of liquid fromsaid source into the well, accordin to the position of the valve.

The primary object of the present invention is accordingly to provide asmooth and workable means and method for keeping brine injection wellsfull of water at all times, thereby avoiding cascading, vacuum formationand gas lock in,

casing or sand.

A specific object of the invention is to provide- Control of the liquidis preferably is simple and comparatively inexpensive, many of the partsbeing preferably of standard equipment useful for other purposes. Thisapparatus preferably includes a combination weight-barcylinder-plungerhaving reduced end portions and an enlarged polished intermediateportion which works with small tolerance in a polished section of thewell tubing. This construction of the plunger has the effect ofsubstantiall reducing the undesirable tendency for the valve to jump upas it unseats, thereby kinking the 'wire line employed in the apparatusand causing such line to break after a few operations. This undesirablefeature is entirely eliminated by the use of the improved form ofplunger in conjunction with a gas lift piston which serves to cushionthe upward movement of the plunger, and to prevent shock or jar at theend of such movement. -Another important feature of the invention is theuse of a single seat for the valve instead of the double seatedarrangement sometimes employed. The single seated arrangement insures acomplete fluid tight connection at all times when the valve is in closedposition.

- Other objects and advantages of the invention will be apparent from aconsideration of the following detailed descrlption taken in conjunctionwith the accompanying drawing, which is intended as illustrative only.

In the drawing:

Fig. 1 is a vertical sectional view partly broken away of an apparatusembodying the invention comprising a surge tank, well casing, tubing andcoacting parts,

Figure 2 is a continuation of Figure 1 in reference to the well casing,tubing and related parts; and

Figures 3 and 4 are sectional detail views, re-

spectively, of two valves used in the operation of the apparatus. I

Referring to the drawing in detail reference numeral i denotes a surgetank or receiving chamber into which water or brine for injection into awell is introduced at A from any suitable source, the water havingpreferably been previously treated for the removal of oil and otherimpurities.

The water or'brine accumulates in the surge tank until the tank isnearly full, or until it reaches the point G, at which level itoverflows through a pipe l5 and provides an hydraulic head at the pointH upon a diaphragm i8 which actuates a normally closed spring-pressedcontrol valve 4. This hydraulic head is suiiicient to open the valveagainst the pressure of its spring P, thereby allowing pressure fluidfrom a source J to flow through the valve from a pipe I9 to the outlet Kand thence through an upright pipe 20 to the lower portion of a cylinder2, which it enters at point L and exerts pressure on the underside of apiston 2a, working in the cylinder 2; The pressure thus applied liftsthe piston in the cylinder 2.

The piston 2-a. is connected through a wire line 3 with a combinationweight-bar-cylirider; valve plunger I located a substantial distancebelow the top of the well. As shown in Figures 1 and 2, the plunger I isprovided with reduced end portions and with an enlarged intermediateportion. This intermediate portion is preferably highly polished andworks with a small tolerance in a correspondingly polished cylindricalsection II of the well tubing I2, just above the ports III. This closefitting plunger 1 provides a resisting piston effect as it is pulledup'a-nd unseats the orifice seat 8, thereby slowing down or braking theupward travel of the weight-bar-cylindervalve plunger 1, thus preventingkinking and breaking of wire line 3. The lower end of the plungerisreduced in size and tapers to a point so as to tightly flt'an opening inthe valve seat 8 which is located within the lower portion of thesection II, preferably at a point of juncture between the said polishedsection and a lower section which extends downwardly as at F toward theporous formation at the bottom of the well. The plunger 1 is ofsubstantial weight, so that when the pressure fluid is released frombelow the piston 2a. the lower end of the plunger will tightly fit theopening in the valve seat. If desired additional weighting may besecured by atand a continuous column of liquid is insured from thepacking 8 back to the surge tank I, so long as the opening in the valveseat 8 remains closed by the tip of the plunger 1, and since the packingis located at or below the static water level, the column of liquidis'continuous from the porous formation at the bottom of the well to thesurge tank.

When the orifice in the valve seat 8 is uncovered water from the surgetank I flows out from the point B and travels through pipe II, enteringthe injection well casing Is at the point C, Water moves down theannular space between the outer casing I3 and the well tubing I2 andenters the ports I0 (Fig. 2), and thence flows past the reduced lowerportion of the plunger I through the opening in the valve seat 8 andinto the bore of the injection well at the point F.

Assuming that the well is taking water faster than it is beingintroduced into the surge tank I, the liquid level in the tankimmediately begins to fall away from the point G and continues to loweruntil it reaches a predetermined level I, at which time the valve 4 willbe automatically closed by the spring P, thus cutting off the supply ofpressure fluid from source J to the under side of the piston 2a, whileat the same time the exhaust port M of control valve 4 is opened,allowing the pressure fluid from beneath the piston 2a to escape throughthe port M, whereupon the weight of the plunger I causes it to fall,thereby closing the opening in the valve seat 8 I and preventing anyfurther liquid from draining taching another weighted member to the wireline 3, although ordinarily this is not necessary as the weight of theplunger itself is sumcient. The top of the cylinder II is preferablyclosed fluid tight. The improved construction of the plunger as hereindescribed insures the smooth operation of the plunger as it is raised touncover the opening in the valve 8 on the application of pressure fluidbeneath the piston 2-a. The usual "jumping" reaction due to unseating asingle seated valve is entirely avoided by this arrangement. It willthus be appreciated that when the piston 2-a is forced upwardly bypressure fluid entering at L the plunger I will be raised with a smoothand even movement and the opening in the valve seat 8 will be uncovered.

As shown the valve seat 8 is located in the injection well just abovethe packer element 8 interposed between the inner tubing II and theouter casing I3. The packer 9 and valve seat 8 are preferably located ata point in the well approximately at or below the normal static waterlevel. The raising of the plunger I. permits any liquid which hasaccumulated in the space between the tubing and casing above the packer8 to flow through the valve seat to the porous formation at the bottomof the well, the liquid entering the tubing II through the ports In justabove the valve seat 8. The water is forced into the porous sand byreason of the hydrostatic pressure of the water in the casing I3 and inthe pipe line I! above.

As shown, the annular space between the casing it and the tubing II andI2 is connected to the bottom of the surge tank I by means of the pipeI'I leading from an inlet point B at the bottom of the surge tank I to adischarge point C at the well casing. The pipe I! is unobstructed outfrom the tank 13. Thus a column of liquid is maintained at all times:from the porous formation at the bottom of the well to the source ofliquid in the tank I, it being understood that the packer 8 and valveseat 8 are located at or above the normal static water level of thewell.

During the period when the liquid level in the tank I is declining fromthe point G to the point I the hydraulic head bearing upon the upperportion of the diaphragm I8 is maintained constant by means of suitablefloat control mechanism located within the surge tank I. However, assoon as the liquid level reaches the point I the hydraulic head in thepipe I5 immediately begins to fall until it fails to balance the springP, whereupon the spring immediately closes the valve 4 as previouslydescribed.

As shown, a pipe I4 extends laterally from the point I within the surgetank I, and communicates with the upper portion of the diaphragm I8.,Pipe. IS-connects with the pipe I4 intermediate its ends. The inlet tothe pipe I4 from the tank I is controlled by means of a valve 5 actuatedby a float 6, the valve being closed when the float is raised, andopened when the float falls. Thus as soon as the liquid level within thetank I rises above the point I the float is raised and the valve 5 isthereby closed, and remains closed during the succeeding rise in theliquid level and until the level again falls to the point I. As theliquid level reaches the point G liquid overflows through the pipe I5 aspreviously described, thus providing an hydraulic head which unbalancesthe spring P, thereby opening the valve 4, raising the piston 2a andunaovering the opening in the valve seat 8, whereupon the liquid fromthe tank I is discharged into the well through said opening. The liquidlevel in the tank begins to fall, assuming that the drainage exceeds thein flow, and the level continues to fall until it reaches the point I inthe tank during which period the float valve 5 continues closed.

polished section of the well tubing. thereby pro- I When the level I isreached the float 8 drops, opening the valve l and allowing water todrain back into the tank from the pipe i5, thereby reducing thehydraulic head upon the diaphragm l8, allowing the valve d to close,'cuttingofl pressure fluid from source J to the piston 2a and allowingthe accumulated'fluid in the pipe 29 to drain through the outlet M,whereupon the control valve within the well is again closed and theliquid level within the tank B again begins to rise. This cycle oroperations is repeated as long as liquid flows into the surge tank frompipe A.

In order to insure hydraulic control only oi the motor valve :8,unafiected by gas pressure, it is necessary to equalize all gaspressures, and this is accomplished according to the present inventionby applying gas pressure to the under side of the diaphragm l8 equal tothe gas pressure above the column of liquid in the surge tanlr i. Thisis accomplished by means of a branch pipe i6 leading from a point N in agas pressure pipe communicating with the top or the tank 0, the otherend of the pipe I6 communicating with the lower portion of the diaphragmit. Thus the same gas pressure is applied above andbelow the diaphragmit, these pressures balancing each other and leaving only the hydraulicpressure applied through the column id as the eilective forceducing abraking effect on the upward travel of th plunger as the valve orificeis uncovered by same.

3. Apparatus for use in a brine disposal well comprising a well tubinghaving a valve seat therein and'provided with a central valve opening,said tubing including an interiorly polished portion extending asubstantial distance above comprising a well tubing having a valve seatapplied to the upper portion of the diaphragm Id.

By the above arrangement there is provided a comparatively simpleconstruction for accomplishing the desired results. The three-portdiaphragm motor valve 4 is economical in construction and eliminates thenecessity for a plurality of which features are vitally necessary forthe proper functioning of the three-port motor valve. It has beendemonstrated by experiment that if pressure is allowed to build upgradually on the diaphragm it as the level rises in the surge tank thevalve 6 only partly opens and tends to stick in the neutral zone,leaving both the gas inlet J and exhaust opening M both partiallyfunctioning, which renders the operation of the system unsatisfactory.

While the disclosure presents a practical working embodiment of anapparatus designed to carry out the advantages and features herein shownand described, it is evident that the invention may be modified to someextent, such as would be within the scope and meaning of the claimsappended hereto.

What is claimed is:

1. In a liquid disposal system for oil fields,'ineluding a disposalwell, alwell casing and well tubing within the casing, a valve seatwithin said tubing and having a valve opening therethrough, and areciprocable valve for coacting with the opening in said valve seat,comprising a weighted plunger havingan enlarged portion snugly fittingthe tubing and a reduced end portion adapted,

"1 wherein the enlarged portion of the plunger is smoothly polished andco-acts with a similarly therein below the normal static water level andprovided with a central valve opening, said tubing including aninteriorly polished portion extending a substantial distance above saidseat, and a weighted valve reciprocable within said polished sectioncomprising a plunger having an enlarged polished portion snugly fittingthe cylinder, and having a reduced end portion adapted to close saidopening when the plunger is in lowered position, a gas actuated pistonlocated directly above the plungenand a flexible cable connecting theplunger to the piston,

5. In a device of the character described, vertically disposed tubing, avalve seat within said tubing having a central opening therethrough, aweighted valve coacting with said seat comprising an elongated plungerhaving a reduced end portion adapted to close said opening, and anenlarged elongated portion above the reduced portion snugly fitting saidtubing, and means for raising the valve to uncover said openingcomprising a closed cylinder located above said tubing in axialalignment therewith, a piston slidable in said cylinder, a flexiblecable connectingsaid piston and said plunger, and means for supplyingfiuid Pressure beneath said piston to raise the same, thereby liftingthe plunger and uncovering the valve seat, said plunger and said tubinghaving coacting polished surfaces whereby friction is reduced.

6. In an apparatus of the class described the combination with a wellcasing and tubing; of a cylinder connected to the tubing and having apolished plunger reciprocally mounted to slide in the cylinder, a valveseat below the plunger having an opening providing a passageway to awell bore, a cylinder having a piston mounted therein, a wire lineconnecting the piston to the plunger, said cylinder in which the plungermoves being interiorly polished, the plunger and piston being'movableunder pressure to open and close said valve seat opening.

7. In an oil well, in combination with vertical tubing having a portionof uniform bore, a valve seat within said portion having a central valveopening, valve means for controlling the flow of fluid through saidopening comprising a weighted plunger having an enlarged portion snuglyfitting the tubing, and having a reduced end portion adapted to closethe opening when the plunger is lowered, and means including a flexiblecable attached to the upper portion of the plunger for raising theplunger to open the valve, the enlarged portion of the plunger engagingthe wall of the tubing with an amount of friction sufflcient to exert abraking action as the plunger is with sufllcient friction to exert abraking action;

as the plunger is raised but not sufllcient to prevent the plunger fromdescending by gravity when no outside force is being exerted thereon,

and means including a flexible cable attached to the upper portion ofthe plunger for. raising the same to open the valve.

9. In an oil well, in combination with vertical tubing having a portionof uniform bore, a valve seat within said portion having a central valveopening, and valve means for opening or closing said opening to controlthe flow of fluid therethrough, comprising an elongated weightedpiunger'having a reduced end portion adapted to close the opening whenthe plunger is lowered and having a body portion fitting said tubingwith suflicient friction to exert a braking action as the plunger israised but not suificient to prevent the plunger from descending bygravity when no outside force is being exerted thereon, and liftingmeans for said plunger including a same, and having an enlarged bodyportion trictionally engaging the wall of the tubing to thereby exertabrakingeflect on the travel of the plunger, and means including aflexible cable attached to the upperportion of the plunger for raisingthe plunger.

11. A device as set forth in claim 10, wherein the enlarged portion ofthe plunger is smoothly polished and coacts with a similarly polishedportion of the tubing.

12. Apparatus for use in a brine disposal well comprising a 'well tubinghaving a valve seat therein and provided with'a central valve opening,said tubing including an interiorly polished portion extending asubstantial distance above said seat, and a weighted valve reciprocablewithin said polished section comprising a plunger having anenlargedepolished portion snugly fltting the cylinder, and having an endportion adapted to close said opening when the plunger is in loweredposition, a fluid actuated piston located above the plunger, and aflexible cable connecting the plunger to the piston.-

13. In an apparatus of the character described, a vertically disposedtubing having a valve seat therein and provided with a central valveopening, said tubing including an interiorly polished portion extendinga substantial distance above said seat, and a weighted valvereciprocable within said polished section comprising a plunger 4 havingan enlarged polished portion snugly fitflexible cable secured to theupper end thereoiw 10. A device of the character described comprising anupright tubing having a valve seat therein, a weighted plunger adaptedto reciprocate in said tubing, including a reduced end portion adaptedto fit said valve seat to close the ting the cylinder, and having areduced end portion adapted to close said opening when the plunger is inlowered position, a fluid actuated

